Field of the Invention
The present invention relates generally to a construction of a knowledge base in an expert system and, more particularly, to a knowledge acquisition support system and method for supporting the operation to generate rules exhibiting high usability with high efficiency from a set of plural cases accumulated.
A knowledge acquisition technique for generating rules of an expert system from the accumulated cases is introduced in a paper titled "Utilized Rule Induction for Extracting Knowledge from Cases and Prospective Other Methods", pp.46-55, Spring Issue, Nikkei AI, separate Vol., 1990. With the advancement of utilization of expert systems, it is desired to establish a methodology of acquiring the knowledge and reducing a load of the knowledge acquisition for constructing the knowledge base, which is a key for making the expert system construction successful or unsuccessful.
In general, the knowledge acquisition in the expert system involves, it is said, the following five steps classified roughly.
Step 1: Collecting concrete cases and processing procedures from knowledge sources (documents, human experts, etc). PA1 Step 2: Rearranging the collected cases and processing procedures. PA1 Step 3: Generalizing and regularizing the rearranged cases and processing procedures. PA1 Step 4: Verifying, adding and modifying the generalized and regularized knowledge. PA1 Step 5: Transforming the knowledge of Step 4 into knowledge expressions such as rules and frame and storing them in a knowledge base.
A rule induction technique known as one of the knowledge acquisition techniques which are now at the stage of utilization is capable of supporting a range of Steps 2-5. As a matter of fact, however, the knowledge engineers and human experts having high-level knowledge still perform important operations to construct the knowledge base of the expert system such as rearranging the cases for use, evaluating the generated rules and determining the information to be acquired next.